Co-existence, Demography and Distribution Patterns of Two Co-occurring Ecologically Equivalent Fynbos Proteaceae Species

Abstract

Leucospermum conocarpodendron (L.) Beuk. and Mimetes fimbriifolius Salisb. ex J.Knight co-occur in the southern Cape Peninsula, where we studied their distribution patterns, demography and fire responses. Leucospermum conocarpodendron has relatively larger seedlings and is therefore the likely competitive dominant. Adults and seedlings of both species are widely spaced and interspecific competition is unlikely to cause competitive exclusion. Differences between the two species in recruitment levels and fire-mortality are small. Thus their size-class distributions are very similar. They are restricted to shallow-soil rocky habitats, not only because of reduced fire intensity in these sites, but because these are habitats avoided by the faster growing more competitive reseeding Proteaceae. Co-existence of these two species appears to mainly be due to fire keeping populations sparse, and ants keeping individuals fairly isolated.